Abstract: Techniques and systems are provided for deriving one or more sets of affine motion parameters at a decoder. For example, the decoder can obtain video data from an encoded video bitstream. The video data includes at least a current picture and a reference picture. The decoder can determine a set of affine motion parameters for a current block of the current picture. The set of affine motion parameters can be used for performing motion compensation prediction for the current block. The set of affine motion parameters can be determined using a current affine template of the current block and a reference affine template of the reference picture.

Abstract: A video decoder can be configured to determine that a block of video data is encoded using a bi-directional inter prediction mode; determine that the block of video data is encoded using a bi-directional optical flow (BIO) process; inter predict the block of video data according to the bi-directional inter prediction mode; perform the BIO process for the block, wherein performing the BIO process for the block comprises determining a single motion vector refinement for a group of pixels in the block, wherein the group of pixels comprises at least two pixels; refine the group of pixels based on the single motion vector refinement; and output a BIO refined predictive block of video data comprising the refined group of pixels.

Abstract: An example device for decoding video data includes a memory configured to store video data, and a video decoder implemented in circuitry and configured to determine that motion information of a current block of the video data is to be derived using decoder-side motion vector derivation (DMVD), determine a pixels clue for the current block, the pixels clue comprising pixel data obtained from one or more groups of previously decoded pixels, derive the motion information for the current block according to DMVD from the pixels clue, and decode the current block using the motion information. The video decoder may generate the pixels clue using multiple hypothesis predictions from multiple motion compensated blocks. The video decoder may determine an inter-prediction direction for the motion information according to matching costs between different prediction directions. The video decoder may refine the motion information using a calculated matching cost for the pixels clue.

Abstract: A video decoder determines a current block of a current picture of video data has a size of P×Q, wherein P is a first value corresponding to a width of the current block and Q is a second value corresponding to a height of the current block, wherein P is not equal to Q, wherein the current block includes a short side and a long side, and wherein the first value added to the second value does not equal a value that is a power of 2; decodes the current block of video data using intra DC mode prediction, wherein decoding the current block of video data using intra DC mode prediction comprises performing a shift operation to calculate a DC value and generating a prediction block for the current block of video data using the calculated DC value; and outputs a decoded version of the current picture.

Abstract: A method of decoding video comprising: receiving an encoded block of video data, determining a transform for the encoded block of video data, wherein the transform has a size S that is not a power of two, rounding S to a power of two creating a transform with a modified size S?, applying an inverse transform with the modified size S? to the encoded block of video data to create residual video data, and decoding the residual video data to create decoded block of video data.

Abstract: For a bi-directional inter predicted block, a video decoder is configured, using a first MV, to locate a first predictive block in a first reference picture; using a second MV, locate a second predictive block in a second reference picture; for a first sub-block of the first predictive block, determine a first amount of bi-directional optical flow (BIO) motion; determine a first final predictive sub-block for the block of video data based on the first amount of BIO motion; for a second sub-block of the first predictive block, determine a second amount of BIO motion; determine a second final predictive sub-block for the block of video data based on the second amount of BIO motion; and based on the first final predictive sub-block and the second final predictive sub-block, determine a final predictive block for the block of video data.

Abstract: Methods, apparatuses, and computer-readable medium are provided for a frame rate up-conversion coding mode, where a bilateral matching mode can be used to determine motion information. In various implementations, local illumination compensation is disallowed from being used for a block when a bilateral matching mode is used for the block. In various implementations, a bilateral matching mode is disallowed from being used when local illumination compensation is used for the block.

Abstract: Methods, apparatuses, and computer-readable medium are provided for a frame rate up-conversion coding mode, in which an affine motion model is applied when conducting bilateral matching. The frame rate up-conversion coding mode can include generated additional frames from frames provided in a bitstream. In various implementations, bilateral matching includes, for a current block in a frame that is being generated, identifying a first block in a first reference picture a second block in a second reference picture. Affine (e.g., non-linear) motion information can be determined as between the first block and the second block. The current block can be predicted using the affine motion information.

Abstract: Techniques and systems are provided for processing video data. For example, a current block of a picture of the video data can be obtained for processing by an encoding device or a decoding device. A pre-defined set of weights for template matching based motion compensation are also obtained. A plurality of metrics associated with one or more spatially neighboring samples of the current block and one or more spatially neighboring samples of at least one reference frame are determined. A set of weights are selected from the pre-defined set of weights to use for the template matching based motion compensation. The set of weights is determined based on the plurality of metrics. The template matching based motion compensation is performed for the current block using the selected set of weights.

Abstract: Techniques and systems are provided for processing video data. For example, a current block of a picture of the video data can be obtained for processing by an encoding device or a decoding device. A parameter of the current block can be determined. Based on the determined parameter of the current block, at least one or more of a number of rows of samples or a number columns of samples in a template of the current block and at least one or more of a number of rows of samples or a number columns of samples in a template of a reference picture can be determined. Motion compensation for the current block can be performed. For example, one or more local illumination compensation parameters can be derived for the current block using the template of the current block and the template of the reference picture.

Abstract: Techniques and systems are provided for processing video data. For example, video data can be obtained for processing by an encoding device or a decoding device. Bi-predictive motion compensation can then be performed for a current block of a picture of the video data. Performing the bi-predictive motion compensation includes deriving one or more local illumination compensation parameters for the current block using a template of the current block, a first template of a first reference picture, and a second template of a second reference picture. The templates can include neighboring samples of the current block, the first reference picture, and the second reference picture. The first template of the first reference picture and the second template of the second reference picture can be used simultaneously to derive the one or more local illumination compensation parameters.

Abstract: An example device includes a memory to store the video data, and processing circuitry in communication with the memory. The processing circuitry is configured to compare a value of a dimension of a current block of the stored video data to a value of a corresponding dimension of a neighboring block of the current block to obtain a relative dimension value. The processing circuitry is further configured to determine, based on the relative dimension value, that the current block is to be partitioned according to a prediction tree (PT) portion of a multi-type tree-based partitioning scheme. The PT portion comprises partitioning according to one of a binary tree structure or a center-side triple tree structure. The processing circuitry is further configured to partition, based on the determination, the current block according to the PT portion, to form a plurality of sub-blocks.

Abstract: A video coding device generates first and second components of a current picture. Additionally, the video coding device determines a first parameter and a second parameter. The first and second parameters are each based on a value of a current sample in the first component. The video coding device applies a cross-component filter to the current sample, thereby determining a filtered value of the current sample based on the first parameter, the second parameter, and one or more cross-component samples. Each of the one or more cross-component samples is in the second component.

Abstract: An example method includes obtaining, for a current block of video data, values of motion vectors (MVs) of an affine motion model of a neighboring block of video data; deriving, from the values of the MVs of the affine motion model of the neighboring block, values of predictors for MVs of an affine motion model of the current block; decoding, from a video bitstream, a representation of differences between the values of the MVs of the affine motion model for the current block and the values of the predictors; determining the values of the MVs of the affine motion model for the current block from the values of the predictors and the decoded differences; determining, based on the determined values of the MVs of the affine motion model for the current block, a predictor block of video data; and reconstructing the current block based on the predictor block.

Abstract: An example device for decoding video data includes a video decoder configured to decode one or more syntax elements at a region-tree level of a region-tree of a tree data structure for a coding tree block (CTB) of video data, the region-tree having one or more region-tree nodes including region-tree leaf and non-leaf nodes, each of the region-tree non-leaf nodes having at least four child region-tree nodes, decode one or more syntax elements at a prediction-tree level for each of the region-tree leaf nodes of one or more prediction trees of the tree data structure for the CTB, the prediction trees each having one or more prediction-tree leaf and non-leaf nodes, each of the prediction-tree non-leaf nodes having at least two child prediction-tree nodes, each of the prediction leaf nodes defining respective coding units (CUs), and decode video data for each of the CUs.

Abstract: In one example, an apparatus for encoding video data includes a video encoder configured to select an intra-prediction mode to use to encode a block of video data, determine whether the block includes a sub-block of a size for which multiple transforms are possible based on the size of the sub-block and the selected intra-prediction mode, when the block includes the sub-block of the size for which multiple transforms are possible based on the size of the sub-block and the selected intra-prediction mode, select one of the multiple possible transforms, transform the sub-block using the selected one of the multiple possible transforms, and provide an indication of the selected one of the multiple possible transforms for the size of the block.

Abstract: In one example, an apparatus for encoding video data includes a video encoder configured to scan a two-dimensional block of transform coefficients to produce a one-dimensional vector of the transform coefficients, determine values indicative of whether the transform coefficients in the one-dimensional vector are significant; and entropy encode at least one of the values using a context model selected based on at least a percentage of significant coefficients in a predetermined number of the values encoded before the at least one of the values.

Abstract: In one example, an apparatus for encoding video data includes a video encoder configured to select an intra-prediction mode to use to encode a block of video data, determine whether the block includes a sub-block of a size for which multiple transforms are possible based on the size of the sub-block and the selected intra-prediction mode, when the block includes the sub-block of the size for which multiple transforms are possible based on the size of the sub-block and the selected intra-prediction mode, select one of the multiple possible transforms, transform the sub-block using the selected one of the multiple possible transforms, and provide an indication of the selected one of the multiple possible transforms for the size of the block.

Abstract: This disclosure describes techniques for mitigating rounding errors in a fixed-point transform associated with video coding by applying a variable localized bit-depth increase at the transform. More specifically, the techniques include selecting a constant value based on a size of a fixed-point transform in a video coding device and applying a variable localized bit-depth increase at the transform with a value equal to the constant value. Applying the variable localized bit-depth increase includes left-shifting a transform input signal by a number of bits equal to the constant value before the fixed-point transform, and right-shifting a transform output signal by a number of bits equal to the constant value after the fixed-point transform. The constant value is selected from a plurality of constant values stored on the video coding device. Each of the constant values is pre-calculated for one of a plurality of different transform sizes supported by the video coding.

Abstract: In one example, an apparatus for encoding video data includes a video encoder configured to calculate a residual block for a block of video data based on a predicted block formed using an intra-prediction mode, and transform the residual block using a transform mapped from the intra-prediction mode. In another example, an apparatus includes video encoder configured to receive an indication of a first intra-prediction mode in a first set of intra-prediction modes for a block of video data, determine a second intra-prediction mode from a second set of intra-prediction modes, smaller than the first set of intra-prediction modes, to which the first intra-prediction mode is mapped, determine a directional transform to which the second intra-prediction mode is mapped, and apply the directional transform to residual data of the block.